"At first I was astonished and then angry as I was stuck with £80 of unusable notes, " complained John from Tenby, Pembrokeshire.

The Co-op told John he had to ask his own bank, Lloyds, to exchange them. "But they refused and directed me to the police station. But the police just looked at me blankly.What can I do to get my proper money?" he appealed to Crusader.

The Co-operative Bank has now refunded John but the mystery remains how he ended up with the flaming booty. However, it may relate to an armed robbery of security guards topping up a Co-op cash machine nearby a few days before John's problem encounter. The raiders risked the stolen cash being sprayed with red dye when they forced open the cases containing it.

"It is suspected these notes entered the distribution channel in the bullion centre in error instead of being destroyed, " said a Co-operative Bank spokeswoman.